Soil conditioning



United States Patent SOIL CONDITIONING Keith L. Smith, Charleston, W. Va., assignor to Union Carbide Corporation, a corporation of New York No Drawing. Application April 15, 1953, Serial No. 349,088

8 Claims. (Cl. 47-58) The present invention relates to methods of improving the granule stability of surface soils.

The problems encountered in the conditioning of soils have been discussed heretofore in U. S. Patent No. 2,625,- 529, issued January 13, 1953, to R. M. Hedrick and D. T. Mowry. According to this disclosure, the tilth of surface soils is improved by mixing the soil with a small amount of synthetic water-soluble polymers having average molecular weights in excess of 10,000. While these polymers :are effective for this purpose, they are relatively expensive materials, which limits their wide-spread adaptability. In addition, water-solutions of these polymers are highly viscous, which makes it difficult to apply them in this manner. On the other hand, if the polymers are applied to the soil in solid form, their hygroscopicity causes them to sorb water :and form gummy masses. Such masses are difficult to apply and also to work into the soil.

According to this invention, a class of materials for soil conditioning has been found which are relatively low molecular weight products compared to the above-described polymers and which are not necessarily watersoluble. Despite their difference in character from the polymers previously used, these materials have the ability to stabilize soil granules against the action of water and otherwise condition the soil to improve its tilth. The undesirable action of Water on soil granules includes several processes. Initially water causes the soil granules to break down or slake to primary soil particles or smaller granules. Secondly, these primary soil particles and very small soil granules tend to plug the capillary pores in the soil. Such plugging adversely atfects the drainage, aeration, friability and erosion resistance of the soil. In soils of high granule stability, these eifects are less pronounced. By incorporating small amounts of the materials of this invention in the'soil, its granule stability can be markedly improved.

The materials of this invention comprise rosin acid or acids or the salts thereof including the inorganic and amine salts of rosin acid. By rosin acid broadly, I include wood rosins, commercial abietic acid, the abietic acid of tall oil whether isolated or not, the hydrogenated, oxidized, heat-treated, polymerized or dehydrogenated products of rosin acid; and the various rosin-acid con-. taining waste products and by-products. The salts of the rosin acids may include any of the metal salts, but the sodium, zinc, cupric, ammonium, calcium, magnesium,

and potassium salts are preferred. Also useful are the barium, cobalt, lead and ferric salts. Among the amine potassium salts are water-soluble, but the zinc, cupric,

magnesium and calcium salts are water-insoluble.

a l0-mesh sieve.

, 2,799,973 Patented July 23, 1957 "ice TABLE I Granule retention of Calhoun silt soil treated with 0.1% on dry soil weight of the sodium salts of different organic acids Granule Retention, Percent Treatment Material Control, no treatment; Sodium itaconate. Sodium barhituratn Sodium ninnamafa Sodium levulinate Sodium citr Sodium wallet-n Sodium non mate Sodium mercaptopropionate Sodium iumarate Sodium glycolate- Sodium furoaten Sodium pyrogallate Sodium sorbate Sodium tetrahydrotoluate Sodium sebacate; Sodium succlnate- Sodium suliamate Sodium l-naphthyl-l-sulfouate Sodium tarmato Sodium paleosulfonate Sodium nicotiuate Sodium 2-naphthy1amine-l-sulfonate Sodium thiosalicylate Sodium thioglycolate Sodium snlfnnilate Sodium pyruvate Sodium myristate Sodium l-amiuoS-naphthol 3,6-disulfouate Sodium salt of commercial abietic acid The following is a description of the soil granule stability test referred to in this specification: V

Soil to be used in a granule stability test is first dried at 70 C. under vacuum and then pulverized to pass a 20-mesh sieve. To 50 grams of this soil is added a solution or dispersion of 0.05 grams (or other test quantity) of treatment material in 15 ml. of tap water. This is thoroughly mixed with a stiif spatula and extruded through The extruded soil filaments are then dried in a forced-convection oven at room temperature and pressure for about 48 hours. Twenty-five grams of this material are then weighed out and placed in a 1000 ml. graduate containing 600 ml. of water. The cylinder is upended once, and allowed to stand for 30 minutes. The

cylinder is then upended 30 times and the contents poured onto a 60-mesh sieve. The sieve and its contents are then raised and lowered into and out of a pan of water for.

30 times. The amount of soil on a dry basis remaining on the sieve is then determined. The weight of this soil, divided by 25 grams, times 100, equals the percentage soil granule stability or soil granule retention.

The effect of soil conditioners in improving soil granule CLASSIFICATION on some Sands Silts Loamy sands Silty clay loams Sandy loams Silty clays San c y l arn Cl y l ms L am .Sa d p ays $ilt loarns Clays The rosin acids and their salts have been tested as soil granule stability a-ge-nts with numerous soil series representative of most of these texture classes. In general, in common with other soil conditioning agents, they are more effective with soils of intermediate texture, and less efiective with the sands angl glays. While the agents of this invention are relatively effective in conditioning a l al ost al ty e of 941 texture .they.e.. .t -y 19 e vs f. rive! Ttl t .In i e ell ori l soil granule stability tests are given for all-. type s of oil tex u e u in .sadiw. b .etate.uwnnina isu i l th n29. 1- mercialsoil conditioner which is reported to be the mixed cal cim sodium salt of a vinyl .acetate nraleic anhydride copolymer (Krilium 6). In the table, the soil texture is given as well as the number of' soils in each' class tested. The results are an average ofthe te st yalues for each class.

TABLE 1i S011 ranule stabili y tests Wlth .dlfierent .SQIIS Percent Granule Retention Texture Classand Number otSolls V. Tested in Each Class 0.1%80- 0.1% Kri1- Control dium 1 ium 6 Rosinate Sands and loamy sands (4) 23. 85 60.83 36. 55 Sandy loams (4) 26. 15 '72. 8 53. 85 Fine sandy loams.(8) 17. 34 -67. 8 59. 01 Very fine sandy loams v8.-1 83. O 46. 20 Loams (3)... 17. 43 a 70.9 #6. 00 Silt loams (26) 8. 01 7 49.2 61. 22 lts (2) 3. 95 '18. 1 '50. 70 Sllty clay loam 4. 93 64:7 41. 50 Silty clays (2)-- 8.60 75.9 80.40 Clay loams ($2 26.86 53.6 52. 70 ays (9L--. 49.34 59.9 a 68.46

Grand averages 20. 90 57. 09 55.08

As previously indica ed. soils a classifies b the Un t d State De a tm n o A cul ure acc rd n t The rosin acids and their salts are effective conditioning agents at relatively low concentrations, and, .in .fact, are

TABLE IV various concentratianl .Qf QiLl anditieners .-Bercent Concentration on Dry -So' Weight -fi .1. .1

-54.-5 -1 93.3 59.7 02.7, 74.0. 07.0 345.2 48.9 61.8 60.0 sac 52.0 47.0 49.8 .45.5 51..1. 5 -4. 61.8

Tallexfis crystalline abietic acid separatedjrom theothetcqnstituen t s offhtliistilled tall oil (West'Virginia 'Pulp and I'aper Company).

ol'NVX" is-the sodium salt of Vinsol Resin, .which isialresln stilkbot tomacid, softening point (A. S. T. M.) 106 C. (HereulesPowder Compan y Tallso is .thecrude sodiumsalt .oi Liqro, containing35% moisture as wellas occluded black liquor. Li qroiis defined. as undistilledwhole tall oil. In these experiments the amount of Tallso" used is based on contained dry matter (West Virginia Pulp and Paper Company).

.. "Liqro" is defined as undistilled whole tall oil (West Virginia Bulp i 'Pane Comp w- A number of materials containing rosin acid or acids have been tested as soil conditioning agents, and in general the purer materials are the most effective, but mater ials-conta'ining-as low as 40% rosin acid show considerable efiect. The materials tested are shown in Table V to follow.

e lssr s and, wi. .11 a y se s thessfil may n w in re. i e.- De @1 9 se i s is Bose. a t e l a r ng Table -PE FPi sQ L QQ Q ...bi1 ytest 9 .591 o rl ie ee TABLE V V .1 ex u e the Pop s rie 1 Materials .contammg J-OSlll acids as soil conditioners TABLE III Average Granule Granulestability of Pope series soils, effect of soil texture Material jffififig s .4; a ggi l% V a 7 Percent Gramfle-Stsblllty o Bercen ti rsonmexggte Lapduse Con- 0.1% 0.1% None 20.8 1:701 tli rili ggl 50.01 19 '"Tallex" I I 3813 6 Boshiate ".Iimrw 0.2.0 7 "Low Viscosity Whole TallOil 3- r "Rosoil" 33.4 Lqa nysand; .co rntield near 26.,0 41.6 66.4 "lnglusqll,-' -rip e ra e 26.6

. r ver. Sandy o I n- 17-8 .6015, 77 7 Fine sandy loam-.- Cornfieldrecently 11. 4 84. 8 59. 2 flalloil products of various degrees of;reflning by distillation (West .flooded Virginia Pulp and Paper Company). Fine sandy loam 7.0 60.0 56.3 Lora n... v 3.9 72.4 ,saa

river. suuoamn... Cultivated field 1.6- 72.1 75.2

' now in weeds. Silty clay loam"--. d0 1.6 74.9 1 57-5 W W- V wg gg' igfjg -4- 1 s ve a the a ts o os n ae cls ar m e efie tiv sample inunedi-: 9. e ondit qnins agent t an he re in a ids mernselves- Table VI be w g s t s resul on ar ou salts of abietic acid-and rosin acidecontainin g rnaterials.

TABLE VI Efiect of various rosin acid derivatives when added to Paulding clay soil in amounts of 0.1% on the dry soil weight Cupric ahiomfn Ferric anietato Magnesium abietate Potassium abietate Sodium abietate Zinc ahietate Lead ahiotato Salts of Commercial Products Containing Rosin Acid:

Sodium salt of Covoil 1 Sodium salt of Liqro Sodium salt of "RosoiP Sodium salt of Rosoil AH" 1 Sodium salt of Indusoil," Regular Grade L Sodium salt of Indusoil, Triple Distilled- Ammonium salt of Acintol D L Sodium salt of Low Viscosity Whole Tall Oil Sodium salt of rosin still bottoms (Vinsol NVX) 3 Sodium salt of commercial abietic acid 1 Dresinate 214 6 Dresinate 87 6 Dresinate 731 Dresinate 9O 5 Dresinate X 6 Sodium salt of Wood Rosin Grade FF 3 Sodium salt of Staybelite" resin Sodium salt of Belro" resin Sodium salt of 731-D resin Amine Salts of Abietic Acid:

Butyl amine salt of commercial abietic acid Di (2-ethyl hexyl) amine salt of commercial abietic acid. Ethyl amine salt of commercial abietie acid 1 Whole and refined tall oils (West Virginia Pulp and Paper 00.). Refined tall oil (Arizona Chemical Company).

3 Products of Hercules Powder Company.

5 Sodium salts of wood rosins (Hercules Powder Company).

6 Potassium salts of wood rosins (Hercules Powder Company).

7 Hydrogenated wood rosin (Hercules Powder Company).

B Low acid N o. rosin (Hercules Powder Company).

Dehydrogenated rosin (Hercules Powder Company).

With respect to the tests made with crude rosin acidcontaining materials, soil granule stability tests have been made with other materials present or likely to be present in the crude products. These tests, reported below, in-

TABLE VIII CECIL CLAY LOAM SOIL dicate that the rosin acid fraction is the active ingredient of these crude materials.

TABLE VII Effect of other materials in crude rosin-acid-containing materials, when added to Paulding clay soil in amounts of 0.1% on the dry soil weight Average Treatment Material Granule Retention,

Percent Control 20. 8 Sodium oleate.-. 26. 4 Sodium salt of raw linseed oil 15. 1 Sodium salt of pine wood lignln 23. 9

1 Contains linolelc and linolenic acids iound in tall 011.

Another method of investigating soil granular stability is as follows:

Soils were thoroughly air dried at 70 C., under vacuum and pulverized to pass a ZO-mesh sieve. Two hundred grams of the dry soil was placed in a small size pugmill mixer 0n the Brabender plastograph. Varying amounts of water, containing the desired concentration of conditioner material on the dry weight of the soil dissolved in this water, were poured on to the dry soil and the whole mixed in the plastograph at R. P. M. for 15 minutes. This mixture was comp-acted in a standard Harvard miniature compaction tester, using a 20-pound spring load, ten tamps per layer and five layers per cylinder. The compacted soil cylinders were thoroughly air dried at room temperature and pressure. The dried cylinder was dropped into the Brabender plastograph in a preset position at the right end of the pugmill. The soil cylinder was worked in the plastograph until the energy to work curve of this machine attained a substantially constant level. A dry screening analysis was then run on this broken up cylinder, followed 'by a wet sieving. This was done by a machine which raised and lowered the nest of sieves through the water at the rate of 30 R. P. M., and using a 4-inch stroke. Materials were wet sieved for 30 minutes. In both the wet and dry sieving, a nest of U. S. Standard 5, 10, 18, 35 and 60 mesh sieves were used. The results of the tests are reported in Table VIII below.

Soil Cylinder Dry Sieve Analysis-Percent of Total Wet Sieve Analysis, Percent Ratio of compaction Soil Retained on U. S. Standard of Total Soil Retained On Total Soil Ratio of Mesh All Sieves (Dry Basis) Retained Total Soil On All Retained Sieves On Wet After Wet Sieving Treatment Sieving To To The Total Soil Total Soil Density, Moisture Retained Sample Lbs. per Content, 5 10 18 35 60 Thru 5 10 18 35 60 On All Wet Cu. Ft. Percent 60 Sieves Sieved, After Dry Percent Sleviug, Percent Control-no treatmeut 99. 5 4. 4 0.6 1. 6 2. 4 24. 2 22.3 48. 9 0. 0 0.0 2. 7 29. 1 68. 2 66. 4 34. 0 0.1% Krilillm 6 105. 1 3. 2 3. 6 1. 4 2.1 20.4 23.3 49. 2 0.0 0. 0 2. 2 29.8 68.0 64.0 32. 5 0.1% Sodium abietate 104. 6 4. 5 0. 0 0.0 1.2 23.7 22. 9 53. 3 0.0 5. 5 2. 7 27. 3 64. 4 80. 5 38. 0 0.5% Sodium abietate-- 100. 3 5. 9 6.0 l. 6 2. 5 30. 8 23.5 35. 7 8.0 3. 3 7. 0 41. 7 40.0 58.1 47. 8 Control-no treatment-.. 101. 5 7. 2 8.0 2. 7 3. 2 26. l 21. 4 39.0 0.0 0. 0 3. l 30. 7 66. 2 52. 5 32. 1 0.1% Krilium 6 105. 4 8. 5 13. 9 4.0 3. 5 26. 4 22.4 29. 7 0.0 0. 0 3.0 24.0 73.0 48. 5 34. 1 0.1% Sodium abietate- 100. 3 7. 2 3.1 0.9 1. 7 27. 7 23.7 43.0 2. 2 2. 4 3. 3 30. 6 61. 3 74. 8 42. 6 0.5% Sodium oblate-ten--- 103.8 8. 2 11.3 5. 5 4. 7 29.7 20. 6 28.1 16. 5 9. 8 6. 6 24.1 43.0 72.1 53. 2 Control-no treatment--- 108. 9 9. 7 16. 7 5. 5 4. 7 29.8 19. 6 23. 6 0.0 0. 0 2. l 27. 6 70. 3 42. 2 32. 2 0.1% Krilium 6 107. 7 9. 0 4. 4 2. 4 3.1 29. 9 21. 8 38. 4 0.0 0. 0 3. 7 34. 6 61.8 66. 5 40. 9 0.1% Sodium abietate 106. 9 9. 5 4. 6 2.0 2.1 35. 3 26. 1 29. 9 3. 5 4. 4 2. 6 27.8 61.8 60.4 42.3 0.5% Sodium abietate.. 103. 5 8. 9 8.8 3.1 2. 3 31. 9 25. 1 29.1 13.4 8.4 7. 3 21.1 49. 8 87. 5 62. 2 Control-no treatment 112. 2 13. 4 24. 6 10. 1 7. 4 18.9 12.9 26. 1 0. 0 0.0 4. 2 30. 0 65.8 43. 8 32. 3 0.1% Krilium 6 116. 2 11.9 18.2 10.8 7. 1 21.7 14.9 25. 6 0.0 2. 5 8. 3 32. 4 56.8 57. 6 42.9 0.1% Sodium abietate 115. 0 11. 5 16.0 6. 2 7.0 28.1 16.4 26. 2 21.1 13.5 6. 9 22. 4 '36. l 72. l 53. 2 11.9 16. 4 12.0 11. 5 24. 7 15. 2 30. 8 22. 8 l6. 5 13.0 18. 9 28.8 98. 4 68. 1 l3. 6 l5. 5 9. 8 8. 8 22. 4 l4. 6 28.9 34. 0 14. 6 6.0 14. 5 30. 9 87. 4 62. 2 13. 1 22.3 14.0 9. 4 19. 3 11. 7 23.3 30.0 19. 7 12.2 15.8 22. 6 85.5 65. 6 20.0 24.2 9. 3 6. 3 18. 9 13. 9 27.4 0. 0 0. 0 2. 9 27. 9 69. 2 46. 2 33. 6 18. 4 25. 2 8.8 6. 2 19. 0 13.2 26.8 0. 0 1.8 7. 5 40. 4 50. 2 57. 7 42. 2 19.0 24. 5 13.1 8. 3 12.1 13. 8 28.2 38. 2 19. 1 7. 2 8.0 27. 5 77. 8 55. 9 19.0 34. 6 10. 1 5. 1 7. 0 28. 8 17. 5 16. 6 10.5 9. 2 23. 1 40. 6 65. 7 54. 2

;v taiad m that eteeqmmrab etamn ;c de

densities and soil mositure contentsatthe time ing, the ratio of coarse aggregates to fine aggregates after wet sieving is much higher ii rtlie case of samples treated withsodiumrosinate than was the. case where they were. untreated." The total percent soi'li retainedafter wet sieviirg was alsomn'ch higherlin the ease of the treated samples. e

' As indicatedi'n the above tabl'e's'jthie is an optimum' watercontent of the soil at which the addition of the soil conditioner is most beneficial. The soil conditioner is effective at all soil moisture concentrations which exist in ractiee;'butas previously state'dfthere is an optimum? soil moisture content at-which-thebest' resultsrare ob.- tained. Haw/5i; me: soil. moistmecnnt ent: should always he beiowthe plastic limit when the soil conditioner is added; If the soil moisture content is above the plastic limit when the conditioner is added; the soil dries to a hard'mass oftnq agrimgl ural v lue-r, I

From the above description of the invention,, its many advantagesare apparent. Since the rosin acids, and their saltsare'availableinlarge quantities at'low cost, and since they are efiective at low concentrations, soil conditioning ent in the soil or'by lime addition. These Water-insoluble 7 forms retain much of their elfecti'veness, but

preciably lost by leaching.

'What;is claimed is; 1

1 method of improving the stability of granules of agricultural soils suitable for cultivation to the action are not apof water which comprises incorpor ating in said soils conainin i mois u e b l w t pl s c imit fr 0 0.5 to 2 below 0.05% based on s'aid soil of. a rosin acidcom t ,2.

2. The method of improving the stability of granill'es of agricultural soils suitable for cultivation't'o th'eactio'n of 'water which comprises incorporating in said soils containing soil moisture below the plastic limit from 0.005% to below 0.05 based on said soil of a rosin acid salt.

'f3TMethod as claimed in claim 2 in which the rosin? acid salt is sodium-'rosinate: 11: V

4. Method as. claimed. in, claim 2.1'11 which the rosin acid salt is ammonium rosinate; 1 a

1'5. Methodia s. aimedinf claim Zinvvhich the resin acid salt is the. sodium saltof tail" oil.

6. Method as. claimedin claim. 2. in which. the resin acid salt is the sodium salt of wood' rpsin.

7. The method of improving the stability of granules of agricultural soils, suitable'for cultivation tov the action of water which. comprises incorporating in saidso'il's containing soilmoisture below the plastic limit from 0.005% to below 0.05 based on said soil' oi: tall' oil.

8. The method of improving the stability of granules of agricultural. soils suitable for cultivation to the action of water whichcomp'rises incorporating in said soils containing soil moisturebelow the plastic limitfrom 0.005% to below 0.05% based on said soil of an amine salt of rosin acid. a 7

References Cited in thefile of thispatent Mowry et a1. Jan. 13, 

1. THE METHOD OF IMPROVING THE STABILITY OF GRANULES OF AGRICULTURAL SOILS SUITABLE FOR CULTIVATION TO THE ACTION OF WATER WHICH COMPRISES INCORPORATING IN SAID SOILS CONTAINING SOIL MOISTURE BELOW THE PLASTIC LIMIT FROM 0.005% TO BELOW 0.05% BASED ON SAID SOIL OF A ROSIN ACID COMPOUND. 